Davy was born in Penzance in Cornwall in England on 17 December 1778. His family moved to Varfell, near Ludgvan, when he was nine, and in term-time Davy boarded with John Tonkin, his mother's godfather.[1] After the Penzance school he attended Truro Grammar School in 1793 to finish his education under the Rev Dr Cardew, who, in a letter to Davies Gilbert, said dryly: "I could not discern the faculties by which he was afterwards so much distinguished." Davy said: "I consider it fortunate I was left much to myself as a child, and put upon no particular plan of study... What I am I made myself."[4]

After Davy's father died in 1794, Tonkin apprenticed him to John Bingham Borlase, a surgeon with a practice in Penzance. Davy's indenture is dated 10 February 1795. In the apothecary's dispensary, Davy became a chemist, and a garret in Tonkin's house was where he conducted his earliest chemical experiments. Davy's friends said: "This boy Humphry is incorrigible. He will blow us all into the air." His elder sister complained of the ravages made on her dresses by corrosive substances.[4]

John Ayrton Paris remarked that poetry written by the young Davy "bear the stamp of lofty genius". Davy's first preserved poem entitled The Sons of Genius is dated 1795 and marked by the usual immaturity of youth. Other poems written in the following years, especially On the Mount's Bay and St Michael's Mount, are descriptive verses, showing sensibility but no true poetic imagination. Three of Davy's paintings from around 1796 have been donated to the Penlee House museum at Penzance. One is of the view from above Gulval showing the church, Mount's Bay and the Mount, while the other two depict Loch Lomond in Scotland.[5][6]

While writing verses at the age of 17 in honour of his first love, he was eagerly discussing the question of the materiality of heat with his Quaker friend and mentor Robert Dunkin. Dunkin remarked: 'I tell thee what, Humphry, thou art the most quibbling hand at a dispute I ever met with in my life.' One winter day he took Davy to the Larigan River,[7] to show him that rubbing two plates of ice together developed sufficient energy by motion, to melt them, and that after the motion was suspended, the pieces were united by regelation. It was a crude form of analogous experiment exhibited by Davy in the lecture-room of the Royal Institution that elicited considerable attention.[4] As professor at the Royal Institution, Davy repeated many of the ingenious experiments he learned from his friend and mentor, Robert Dunkin.

Davies Giddy met Davy in Penzance carelessly swinging on the half-gate of Dr Borlase's house, and interested by his talk invited him to his house at Tredrea and offered him the use of his library. This led to an introduction to Dr Edwards, who lived at Hayle Copper House. Edwards was a lecturer in chemistry in the school of St. Bartholomew's Hospital. He permitted Davy to use his laboratory and possibly directed his attention to the floodgates of the port of Hayle, which were rapidly decaying as a result of the contact between copper and iron under the influence of seawater. Galvanic corrosion was not understood at that time, but the phenomenon prepared Davy's mind for subsequent experiments on ship's copper sheathing. Gregory Watt, son of James Watt, visited Penzance for his health's sake, and while lodging at the Davy's house became a friend and gave him instructions in chemistry. Davy was acquainted with the Wedgwood family, who spent a winter at Penzance.[4]

Thomas Beddoes and John Hailstone were engaged in a geological controversy on the rival merits of the Plutonian and Neptunist hypotheses. They travelled together to examine the Cornish coast accompanied by Davies Gilbert and made Davy's acquaintance. Beddoes, who had established at Bristol a 'Pneumatic Institution,' needed an assistant to superintend the laboratory. Gilbert recommended Davy, and in 1798 Gregory Watt showed Beddoes the Young man's Researches on Heat and Light, which were subsequently published by him in the first volume of West-Country Contributions. After prolonged negotiations, mainly by Gilbert, Mrs Davy and Borlase consented to Davy's departure, but Tonkin wished him to remain in his native town as a surgeon, and altered his will when he found that Davy insisted on going to Dr Beddoes.

In 1802, Humphry Davy had what was then, the most powerful electrical battery in the world at the Royal Institution. With it, Davy created the first incandescent light by passing electric current through a thin strip of platinum, chosen because the metal had an extremely high melting point. It was neither sufficiently bright nor long lasting enough to be of practical use, but demonstrated the principle. By 1806 he was able to demonstrate a much more powerful form of electric lighting to the Royal Society in London. It was an early form of arc light which produced its illumination from an electric arc created between two charcoal rods.

On 2 October 1798, Davy joined the Pneumatic Institution at Bristol. It had been established to investigate the medical powers of factitious airs and gases, and Davy was to superintend the various experiments. The arrangement agreed between Dr Beddoes and Davy was liberal and enabled Davy to give up all claims on his paternal property in favour of his mother. He did not intend to abandon the medical profession and was determined to study and graduate at Edinburgh but he soon began to fill parts of the institution with voltaic batteries. While living in Bristol, Davy met the Earl of Durham, who was a resident in the institution for his health and became close friends with Gregory Watt, James Watt, Samuel Taylor Coleridge and Robert Southey, all of whom became regular users of nitrous oxide (laughing gas), to which Davy became addicted. The gas was first synthesized in 1772 by the natural philosopher and chemist Joseph Priestley, who called it phlogisticated nitrous air (see phlogiston).[8] Priestley described his discovery in the book Experiments and Observations on Different Kinds of Air (1775), in which he described how to produce the preparation of "nitrous air diminished", by heating iron filings dampened with nitric acid.[9]

James Watt built a portable gas chamber to facilitate Davy's experiments with the inhalation of nitrous oxide. At one point the gas was combined with wine to judge its efficacy as a cure for hangover (his laboratory notebook indicated success). The gas was popular among Davy's friends and acquaintances, and he noted that it might be useful for performing surgical operations.[10]Anesthetics were not regularly used in medicine or dentistry until decades after Davy's death.[11]

Davy threw himself energetically into the work of the laboratory and formed a long romantic friendship with Mrs Anna Beddoes, who acted as his guide on walks and other fine sights of the locality.[12] In December 1799 Davy visited London for the first time and extended his circle of friends.[4]

In the gas experiments Davy ran considerable risks. His respiration of nitric oxide which may have combined with air in the mouth to form nitric acid (HNO3),[13] severely injured the mucous membrane, and in Davy's attempt to inhale four quarts of 'pure hydrocarbonate' gas in an experiment with carbon monoxide he 'seemed sinking into annihilation.' On being removed into the open air, Davy faintly articulated, 'I do not think I shall die,'[13] but some hours elapsed before the painful symptoms ceased.[4] Davy was able to take his own pulse as he staggered out of the laboratory and into the garden, and he described it in his notes as 'threadlike and beating with excessive quickness'.

In this year the first volume of the West-Country Collections was issued. Half consisted of Davy's essays On Heat, Light, and the Combinations of Light, On Phos-oxygen and its Combinations, and on the Theory of Respiration. On 22 February 1799 Davy, wrote to Davies Gilbert, 'I am now as much convinced of the non-existence of caloric as I am of the existence of light.' In another letter to Gilbert, on 10 April, Davy informs him: "I made a discovery yesterday which proves how necessary it is to repeat experiments. The gaseous oxide of azote (the laughing gas) is perfectly respirable when pure. It is never deleterious but when it contains nitrous gas. I have found a mode of making it pure." He said that he breathed sixteen quarts of it for nearly seven minutes, and that it 'absolutely intoxicated me.' During this year Davy published his Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide and its Respiration. In after years Davy regretted he had ever published these immature hypotheses, which he subsequently designated 'the dreams of misemployed genius which the light of experiment and observation has never conducted to truth.'[4]

Davy's later time at the institution was spent partially in experimentation. In 1800, Davy informed Gilbert that he had been 'repeating the galvanic experiments with success' in the intervals of the experiments on the gases, which 'almost incessantly occupied him from January to April.'

In February 1801 Davy was interviewed by the committee of the Royal Institution, comprising Joseph Banks, Benjamin Thompson (who had been appointed Count Rumford) and Henry Cavendish. Davy wrote to Davies Gilbert on 8 March 1801 about the offers made by Banks and Thompson, a possible move to London and the promise of funding for his work in galvanism. He also mentioned that he might not be collaborating further with Beddoes on therapeutic gases. The next day Davy left Bristol to take up his new post at the Royal Institution,[11] it having been resolved 'that Humphry Davy be engaged in the service of the Royal Institution in the capacity of assistant lecturer in chemistry, director of the chemical laboratory, and assistant editor of the journals of the institution, and that he be allowed to occupy a room in the house, and be furnished with coals and candles, and that he be paid a salary of 100l. per annum.'[4]

On 25 April 1801, Davy gave his first lecture on the relatively new subject of 'Galvanism'. He and his friend Coleridge had had many conversations about the nature of human knowledge and progress, and Davy's lectures gave his audience a vision of human civilisation brought forward by scientific discovery. "It [science] has bestowed on him powers which may almost be called creative; which have enabled him to modify and change the beings surrounding him, and by his experiments to interrogate nature with power, not simply as a scholar, passive and seeking only to understand her operations, but rather as a master, active with his own instruments."[11] The first lecture garnered rave reviews, and by the June lecture Davy wrote to John King that his last lecture had attendance of nearly 500 people. "There was Respiration, Nitrous Oxide, and unbounded Applause. Amen!"[11]

Davy's lectures also included spectacular and sometimes dangerous chemical demonstrations for his audience, a generous helping of references to divine creation, and genuine scientific information. Not only a popular lecturer, the young and handsome Davy acquired a huge female following around London, and nearly half of the attendees pictured in Gillray's cartoon are female. When Davy's lecture series on Galvanism ended, he progressed to a new series on Agricultural Chemistry, and his popularity continued to skyrocket. By June 1802, after just over a year at the Institution and at the age of 23, Davy was nominated to full lecturer at the Royal Institution of Great Britain. Garnett quietly resigned, citing health reasons.[11]

Davy was a pioneer in the field of electrolysis using the voltaic pile to split common compounds and thus prepare many new elements. He went on to electrolyse molten salts and discovered several new metals, including sodium and potassium, highly reactive elements known as the alkali metals. Davy discovered potassium in 1807, deriving it from caustic potash (KOH). Before the 19th century, no distinction had been made between potassium and sodium. Potassium was the first metal that was isolated by electrolysis. Davy isolated sodium in the same year by passing an electric current through molten sodium hydroxide. Davy discovered calcium in 1808 by electrolyzing a mixture of lime and mercuric oxide.[17][18] Davy was trying to isolate calcium; when he heard that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. He worked with electrolysis throughout his life and was first to isolate magnesium, boron, and barium.

Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it "dephlogisticated marine acid" (see phlogiston theory) and mistakenly thought it contained oxygen. Davy showed that the acid of Scheele's substance, called at the time oxymuriatic acid, contained no oxygen. This discovery overturned Lavoisier's definition of acids as compounds of oxygen. In 1810, chlorine was given its current name by Humphry Davy, who insisted that chlorine was in fact an element.[19]

Davy revelled in his public status, as his lectures gathered many spectators. He became well known in 1799 due to his experiments with the physiological action of some gases, including laughing gas (nitrous oxide), with enthusiastic experimental subjects including his poet friends Robert Southey and Samuel Taylor Coleridge.[13]

In 1812, Davy was knighted, gave a farewell lecture to the Royal Institution, and married a wealthy widow, Jane Apreece. (While Davy was generally acknowledged as being faithful to his wife, their relationship was stormy, and in later years he travelled to continental Europe alone.) In October 1813, he and his wife, accompanied by Michael Faraday as his scientific assistant (and valet), travelled to France to collect a medal that Napoleon Bonaparte had awarded Davy for his electro-chemical work. While in Paris, Davy was asked by Gay-Lussac to investigate a mysterious substance isolated by Bernard Courtois. Davy showed it to be an element, which is now called iodine.[21][22]

The party left Paris in December 1813, travelling south to Italy.[23] They sojourned in Florence, where, in a series of experiments conducted with Faraday's assistance, Davy succeeded in using the sun's rays to ignite diamond, proving it is composed of pure carbon.

After his return to England in 1815, Davy experimented with lamps for use in coal mines. There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners. In particular the Felling mine disaster in 1812 near Newcastle caused great loss of life, and action was needed to improve underground lighting and especially the lamps used by miners. Davy conceived of using an iron gauze to enclose a lamp's flame, and so prevent the methane burning inside the lamp from passing out to the general atmosphere. Although the idea of the safety lamp had already been demonstrated by William Reid Clanny and by the then unknown (but later very famous) engineer George Stephenson, Davy's use of wire gauze to prevent the spread of flame was used by many other inventors in their later designs. George Stephenson's lamp was very popular in the north-east coalfields, and used the same principle of preventing the flame reaching the general atmosphere, but by different means.[24] Unfortunately, although the new design of gauze lamp initially did seem to offer protection, it gave much less light, and quickly deteriorated in the wet conditions of most pits. Rusting of the gauze quickly made the lamp unsafe, and the number of deaths from firedamp explosions rose yet further.

There was some discussion as to whether Davy had discovered the principles behind his lamp without the help of the work of Smithson Tennant, but it was generally agreed that the work of both men had been independent. Davy refused to patent the lamp, and its invention led to his being awarded the Rumford medal in 1816.[1]

In 1815 Davy suggested that acids were substances that contained replaceable hydrogen ions;– hydrogen that could be partly or totally replaced by metals. When acids reacted with metals they formed salts. Bases were substances that reacted with acids to form salts and water. These definitions worked well for most of the nineteenth century.[25]

Davy's laboratory assistant, Michael Faraday, went on to enhance Davy's work and would become the more famous and influential scientist. Davy is supposed to have even claimed Faraday as his greatest discovery. Davy later accused Faraday of plagiarism, however, causing Faraday (the first Fullerian Professor of Chemistry) to cease all research in electromagnetism until his mentor's death.

Of a sanguine, somewhat irritable temperament, Davy displayed characteristic enthusiasm and energy in all his pursuits. As is shown by his verses and sometimes by his prose, his mind was highly imaginative; the poet Coleridge declared that if he "had not been the first chemist, he would have been the first poet of his age", and Southey said that "he had all the elements of a poet; he only wanted the art." In spite of his ungainly exterior and peculiar manner, his happy gifts of exposition and illustration won him extraordinary popularity as a lecturer, his experiments were ingenious and rapidly performed, and Coleridge went to hear him "to increase his stock of metaphors." The dominating ambition of his life was to achieve fame, but though that sometimes betrayed him into petty jealousy, it did not leave him insensible to the claims on his knowledge of the "cause of humanity", to use a phrase often employed by him in connection with his invention of the miners' lamp. Of the smaller observances of etiquette he was careless, and his frankness of disposition sometimes exposed him to annoyances which he might have avoided by the exercise of ordinary tact.[28]

He spent the last months of his life writing Consolations in Travel, an immensely popular, somewhat freeform compendium of poetry, thoughts on science and philosophy. Published posthumously, the work became a staple of both scientific and family libraries for several decades afterward. Davy spent the winter in Rome, hunting in the Campagna on his fiftieth birthday. But on 20 February 1829 he had another stroke. After spending many months attempting to recuperate, Davy died in a hotel room in Geneva, Switzerland, on 29 May 1829.[1]

He had wished to be buried where he died, but had also wanted the burial delayed in case he was only comatose. He refused to allow a post-mortem for similar reasons. But the laws of Geneva did not allow any delay and he was given a public funeral on the following Monday, in the Plainpalais Cemetery, outside the city walls. Jane organised a memorial tablet for him, in Westminster Abbey shortly afterwards, at a cost of £142.[30][31]

A plaque to honour him is on the wall of the Royal Panopticon of Science and Arts in 1854.

A lunar crater (Davy) is named after Sir Humphry Davy. It has a diameter of 34 km and coordinates of 11.8S, 8.1W.

In his hometown of Penzance, Cornwall, a statue of Davy stands in front of the imposing Market House, (now owned by Lloyds TSB) at the top of the town's main street Market Jew Street. Nearby is a house on which a commemorative plaque claims the location as the site of his birth.

Davy is the subject of a humorous song by Richard Gendall, recorded in 1980 by folk-singer Brenda Wootton, each verse of which recalls one of Davy's major discoveries.

English playwright Nick Darke wrote Laughing Gas (2005) a comedy script about the life of Sir Humphry Davy, unfinished at the time of Nick Darke's death; completed posthumously by actor and playwright Carl Grose and produced by the Truro-based production company O-region.

Davy's passion for outdoors and fly-fishing earned him title "father of modern fly-fishing" and his book Salmonia is often considered as "fly-fisherman bible".

Bentley's first clerihew, published in 1905, was written about Sir Humphry Davy:

^In his 1800 Researches, Chemical and Philosophical (p.556), Davy commented: "As nitrous oxide in its extensitve operation appears capable of destroying pain, it may probably be used with advantage during surgical operations in which no great effusion of blood takes place."

^Fullmer, June Z. (2000). Young Humphry Davy: The Making of an Experimental Chemist, Volume 237. American Philosophical Society. p. 158. ISBN9780871692375. In prominent alliance with his concept, Davy celebrated a natural-philosophic deism, for which his critics did not attack him, nor, indeed, did they bother to mention it. Davy never appeared perturbed by critical attacks on his "materialism" because he was well aware that his deism and his materialism went hand in hand; moreover, deism appeared to be the abiding faith of all around him.